ML021050221

Response to NRC Bulletin 2001-01, Request for Additional Information

ML021050221
Person / Time
Site:	Palo Verde
Issue date:	01/29/2002
From:	Overbeck G Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-04650-GRO/SAB/RJR, IEB-01-001
Download: ML021050221 (4)

Text

1 OCFR50.54(f)

Gregg R. Overbeck Mail Station 7602 Palo Verde Nuclear Senior Vice President TEL (623) 393-5148 P.O. Box 52034 Generating Station Nuclear FAX (623) 393-6077 Phoenix, AZ 85072-2034 102-04650-G RO/SAB/RJ R January 29, 2002 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

References:

1. Letter 102-04603-CDM/SAB/RJR, dated September 4, 2001, "Response to NRC Bulletin 2001-01: Circumferential Cracking of Reactor Pressure Vessel Head Penetration Nozzles," from C. D. Mauldin, APS to USNRC.

2. Letter dated November 5, 2001, "Palo Verde Nuclear Generating Station, Units 1, 2, and 3 - Telephone Conference Summary RE:

Responses to Bulletin 2001-01," from L. R. Wharton, USNRC to G. R. Overbeck, APS.

3. Letter 102-04628-GRO/SAB/RJR, dated December 06, 2001, "Revised Inspection Schedule in Response to NRC Bulletin 2001 -01, from Gregg R. Overbeck, APS to USNRC.

4. Telephone Conferences, dated December 13, 2001 and December 14, 2001, Discussion on Supplemental Response Letter (Reference 3) between APS Staff and USNRC Staff.

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Units 1, 2 and 3 Docket Nos. STN 50-528, 50-529, and 50-530 Response to NRC Bulletin 2001-01 Request for Additional Information On December 13, 2001 and December 14, 2001, telephone conferences were held between staff members of Arizona Public Service Company (APS) and the USNRC to discuss the revised inspection schedule (Reference 3). During these conversations the USNRC staff also requested clarification of the scope of inspection required by NRC Bulletin 2001-01 and asked for more details on the corrective actions and acceptance criteria that APS would use. A subsequent telephone conference between APS and the USNRC staff was held on January 09, 2002, to provide responses to these two items.

U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Consolidated Response to NRC Bulletin 2001-01 Page 2 The purpose of this letter is to document the clarifying information provided during these telephone conferences.

NRC Request:

APS Response:

NRC Request:

APS Response:

Confirm the scope of the inspection of the reactor head penetrations includes an inspection of the head vent nozzle and the J-groove weld.

It is APS' intention to perform 100 percent inspection of the vessel head penetrations (VHP) using a combination of eddy current, liquid penetrant, and ultrasonic examination techniques as necessary. This inspection includes the reactor head vent nozzle. The critical area of the nozzles discussed in Reference 1 includes the wetted surfaces on and near the "J-groove" weld.

Since the January 09, 2002 telephone conference, APS has continued with the detailed planning for performing the inspections on the head vent nozzle. APS has determined that due to the presence of control rod drive nozzle cones in the area of the head vent, the head vent nozzle may have to be examined by an effective visual examination. Therefore, for the head vent penetration, APS is changing its commitment from under the head surface and/or volumetric examinations to either an effective visual examination, or under the head surface and/or volumetric examinations.

Provide clarification on the acceptance criteria that will be used during the inspections and expected corrective actions if suspected through wall cracks are found.

APS is reviewing the proposed "Flaw Evaluation Guideline" for use in evaluating indications that may be found during the upcoming inspections. It is APS' intention that for any penetration where a through-wall crack is suspected, APS will attempt to locate circumferential cracking on the outside diameter above and in the vicinity of the "J-groove" weld. Corrective actions for indications will be based on the applicable regulatory and Code requirements and exemptions that APS has committed to at the time of the inspection and repair.

No new commitments are being made to the NRC by this letter. One commitment is being modified in that the inspection of the reactor head vent penetration will be completed using effective visual inspection or under the head surface and/or volumetric examinations.

U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Consolidated Response to NRC Bulletin 2001-01 Page 3 Please contact Thomas N. Weber at (623) 393-5764 if you have any questions or require additional information.

Sincerely, CDM/SAB/RJR/kg 7f cc:

E. W. Merschoff J. N. Donohew J. H. Moorman

STATE OF ARIZONA COUNTY OF MARICOPA

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I, Gregg R. Overbeck, represent that I am Senior Vice President - Nuclear, that the foregoing document has been signed by me on behalf of Arizona Public Service Company with full authority to do so, and that to the best of my knowledge and belief, the statements made therein are true and correct.

Gre'gg R. Overbeck Sworn To Before Me This _,JDay Of L.

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Notary Public "OFFICIAL SEAL Nora E. Meador Notary Pubifo.Arizona Notary Commission Stamp